Micrometer-calipers.



PATBNTBD fx1-:13.17, 1903,.

R. MILLER. MIGROMETBR GALIPBRS.

APPLICATION FILED AUG. 14, 1902.

NO MODEL.

Wl TNE SSE S EV-A ATTORNEYS.

me nomas mm comoro-Luna. wmdfom u. c.

UNITEDV STATES ArnNr Fries.

RUDOLPH MILLER, OF CHAMBERSBURG, PENNSYLVANIA.

MICRONI ETER-CALEPERS.

SPECIFICATION forming part of Letters Patent No. 720,947, dated February17, 1903. Application lod August 14, 1902:. Serial 110.119.635. (Nomodel.)

To afZZ whom t may concern.-

' Be it known that I, RUDOLPH MILLER, a' citizen of the United States,and a resident of Chambersburg, in the county of Franklin and State ofPennsylvania, have invented new and useful Improvements inMecrometer-Calipers, of which the following is a full, clear, and exactdescription.

My invention relates to micrometer-calipers, my more particular objectbeing to produce a calipers having several nice adjustments for thepurpose of increasing the precision of the instrument. A-

Reference is to be had to the accompanying drawings, forminga part ofthis specication, in which similar characters of reference indicatecorresponding parts in all the figures.

Figure l is a plan view of my calipers. Fig. 2 is an edge elevation ofthe same. Fig. 3 is a View somewhat similar to Fig. 1, but showingcertain parts occupying different relative positions. Fig. 4 is asection, some- What enlarged, upon the line it 4 in Fig. 1 looking inthe direction of the arrows. Fig. 5 is a section upon the line 5 5 ofFig. 1 looking in the directionv of the arrows. Fig. 6 is a Section uponthe line 6 6 of Fig. 1 looking in the direction of the arrows; and Fig.7 is a fragmentary elevation of one of the jaws 16, together withcertain spring mechanism contained therein.

A jaw 1 is provided with a scale 2 and with a point 3. A leaf -LL ismovable relatively to the jaw l and is provided with an arc-scale 5 andwith a head 6. A micrometer-screw 7 passes through the head 6 andengages the plate S, which is integral with the leaf 4E, being separatedtherefrom bya slot 9. By adjusting the micrometer-screw' theindicator-plate 8 maybe moved relatively to the head 6,and therebybrought exactly into alinement With any given graduation upon the scale.The screw 7 thus acts as a micrometer adjustment for the plate 8. Uponthe in place.

Then the needle is moved relatively to the arc-scale, the spring 12 isplaced under greater tension.

A clip-platelet prevents the head 10 from moving asunder from the plateS, and thereby maintains the needle 12 in proper alinement. A screw-stop15 is mounted upon the head lO. A jaw 16, provided with a point 17 andwith an arm 18, is movable relatively to the tirstmentioned jaw. Uponthe extreme upper portion of the arm 18 is mounted a G-shaped spring 19,vthe respective terminais of this spring being provided with micrometerscrews 20 22. By adjusting the screw 2O the G -shaped spring isvirtually rendered larger or smallar, whereby the length of the arm 18is virtually changed within slight limits. The micrometer-screw 22 bearsdirectly upon the screw-stop 15, so that by adjusting the screw 22 theposition of the needle 11 when at rest may be slightly altered. Thescrew 20 therefore serves to adjust the sensitiveness of the needle11,while the screw 22 serves to correct the portion of the needle. Bymeans of the thumb-screw 21 the head 6, and consequently .the leafl 4,may be secured rigidly in position relatively to the scale 2- thatis tosay, the'head 6 may be moved radially along the scale 2 and tightened inposition relatively thereto. The head 6 being thus fixed relatively tothe scale 2, the thumbscrew 7 may be used to force the plate 8 slightlyasunder from the head6, thereby bringing the edge SiL precisely in linewith any graduation upon the scale 2. It will be seen, therefore, thatwhile the screw 2l secures the head 6 in such position that the edge 8g4is substantially at the desired position, yet the use of themicrometer-screw 7 is usually necessary to bring the edge 8f exactlyinposition. The arrangement thus constitutes both a coarse measureadjustment and a micrometer adjustment relatively to the scale 2.

'A thumb-screw 23 is used for the purpose .of clamping the jaw 16 to thelowerl end 4: ofk the leafft, thereby preventing movements between thesame.

A micrometer-screw 24: passes through a spring-post 25 and engages aspring-stop 26, located rigidly upon the member fla. A springstop 26 ismounted within' an aperture 27, so

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that normally the bottom 4fof the leaf 4 has a slight degree of playrelatively to the jaw 16. For this purpose an aperture 28 is made in themember 4, as indicated by dotted lines in Fig. 3. It is clear,therefore, that since by means of the screw 23 the members 4 and 16 maybe clamped rigidly together and by means of the screw 21 the leaf 4 maybe clamped lxedly in position relatively to the jaw 1 the calipers maybe so arranged that either the jaw 16 and the leaf 4 and 4L may becaused toact practically as a single jaw, or the leaf 4 and 4 may berigidly secured to the jaw 1, so that these parts are practicallyintegral, while the jaw 16 may be allowed a slight play relativelythereto.

A pivotal screw 28 is provided with a disk 29 and terminates in a screw30. This pivot is provided with shoulders 30, 30h, and 30,

as indicated more particularly in Fig. 4. A nut 31 engages the screw 30.A spring 32 (shown more particularly in Fig. 7) is secured by means of apin 33 within an aperture 35 of the jaw 16 and is provided with aradiallydisposed end 34, which projects outwardly, as indicated moreparticularly in Fig. 4, and bears against a shoulder upon the member 16.The object of this spring 32 is to normally produce a slight tensionbetween the flat leaf 44 and the jaw 16. The spring normally tends todraw these parts to the position indicated in Fig. 1, the abnormalposition of the parts being indicated in Fig. 3. A spring 37, havingsubstantially the form of a cupped disk, is mounted in the aperture 36and serves to tension the several parts mounted upon the pivot 28a, asindicated in Fig. 4.

My invention admits of quite a variety of uses, some of which areindicated above. Suppose, for instance, it is desired to measure thedegree of expansion in an object. The screw 21 is loosened, the points 3and 17 are placed in contact with the object, the micrometer-screw 24 isadjusted until the needle 11 rests upon one of the graduations of thescale 5, the screw 23 is loosened, unless it should happen to be alreadyloose, and the objects to be operated upon caused to expand. The resultis that the points 3 and 17 are moved slightly asunder, as indicated inFig. 3, the original position having been that indicated in Fig. l. Themovement asunder of the points 3 and 17 causes the arm 18 to moverelatively to the scale 2, as the result of which the micrometer-screw22 presses upon the screw-stop l5 and moves the needle upon thearc-scale 5, as indicated in Fig. 3. A very slight movement asunder ofthe points 3 and 17 is'necessary to give the play of the needleaconsiderable amplitude. The springpost 25 consists of a split post andis employed as any other spring-post.

For certain fine measurements the head 6 is clamped upon the arc 2 bythe screw 21, as above described, the indicating-plate 8 being broughtas nearly as practicable into alinement with any selected graduation ofthe scale. Then by adjusting the screw 7 the plate 8 is moved exactlyinto the position desired, and measurements can thereafter be reckonedfrom the particular graduation thus chosen. This is especially desirablein instances where a plurality of comparative readings are desired-as,for instance, in measuring boards of slightly different thicknesses.

For ordinary uses it is preferable to tighten screw 23 and loosen thescrew 21. This leaves the jaws 3 and 17 free to move toward and fromeach other, as in the ordinary calipers.

It will be observed, therefore, that while my improved calipers hasquite a number of fine adjustments it is by no means necessary to employall of them unless desired. In fact, the instrument admits of all of theuses of ordinary calipers and can be used as rapidly as the same; but incases where desirable the adjustments above described may be called intorequisition.

The instrument may be given great refinement in making measurements.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. A micrometer-calipers, comprising jaws normallyfree to move relative to each other, clamping mechanism for preventingrelative movements of said jaws beyond certain predetermined limits,spring-controlled mechanism for preventing movements of said jaws withinsaid limits, indicator mechanism for exhibiting the degree of saidmovements within said predetermined limits, and a micrometer adjustmentfor controlling the sensitiveness of said indicator mechanism.

2. A micrometer-calipers, comprising jaws normally free to moverelatively to each other, one of said jaws being provided with an arccarrying a scale, a member sandwiched between said jaws and looselyconnected with one of the same so as normally to have a slight playrelatively thereto, said member being provided with an indicator forsaid scale, means, controllable at will, for regulating the degree ofplay between said members and said jaw connected therewith, amicrometric device for measuring the said degree of play, and means forclamping said jaws approximately in a predetermined relative position.

3. A micrometer-calipers, comprising jaws normally free to moverelatively to each other, one of said jaws being provided with an arccarrying a scale, a member sandwiched between said jaws and looselyconnected with one of the same, so as normally to have a slight playrelatively thereto, said member being provided with an indicator forsaid scale, means, controllable at will, for regulating the degree ofplay between said member and said jaw connected therewith, a mi- IOO IIO

erometrie device for measuring the said degree of play, means forclamping said jaws approximately in a predetermined position so thatsaid indicator may occupy a predetermned position leiativeiy to saidseale, and

nlicrometric mechanism for placing said indicator exactly upon saidscale.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing Witnesses.

l RUDOLPH MILLER.

Witnesses:

WM. R. KEEFER, CHARLES G. WEIRICLL

